DE453475C - Device for driving drop bars or similar auxiliary devices in electrical measuring devices - Google Patents

Description

Device for driving drop bars or similar auxiliary devices with electrical measuring devices. The setting force of the measuring mechanism in measuring instruments, especially with direct-pointing electrical measuring devices, is usually very small. It would be uneconomical to make these forces greater than safe movement of the display organ requires. However, they are also automatic from such a measuring mechanism Registration or switching on and off electrical contacts is sufficient the same torques not to overcome the friction of the writing organ or To safely tear loose the contacts, which experience has shown to be easily welded. For registrants The necessary extra work is often achieved by - reinforcing the System torque applied. Both for registering and contact instruments the second possible solution was also used, with the help of a special assistant (Clockwork, Ferrari engine, etc.) to do the extra work. In this case it will Writing or contact organ at regular intervals by an auxiliary device, z. B. a so-called drop bracket, clamped and thereby a point-by-point registration or respective contact made. The invention is a particular one simple and small drive device for the hanger known per se, which consequently fits completely into a normal-sized instrument.

According to the invention, those occurring with temperature changes are very uses significant molecular forces by moving the drop arm through alternate heating and cooling vou bimetal strips is controlled by their Own movement at the same time automatically and alternately switches on its own electrical heating and is turned off.

The drawing shows an example for the new facility shown. It consists of a bimetal piece, expediently a bifilar spiral a, through which the secondary current of a small transformer b flows. The primary stream closes via a pin d, which is isolated from the crank c and which is connected to the one Primary terminal of the transformer b is connected, a contact e in the rocker arm f and the tension spring g. When the coil a is heated, its axis rotates in the direction of the arrow, the pin d finally tilts the switch and interrupts the primary current. The pen d now comes on the insulated side of the toggle switch f to lie, the spiral rotates its axis as a result of cooling in a retrograde direction, until the rocker arm tilts back and closes the primary flow, whereupon the whole thing Play itself over and over again. The two bimetal strips hh are with the spiral a connected in series and therefore move a drop bracket i over in unison the contact or writing element k up and down. A series connection of the drop bars multiple instruments is possible.

The rotary movement of the spiral a can also be performed mechanically by means of cams, The linkage etc. or indirectly drive the drop bracket via an electro-magnet. In this case, the bimetal springs are replaced by simple leaf springs or hinges. The switch f shown in the figure can be replaced by another Momentary switch, e.g. B. a mercury toggle switch to be replaced. In place the transformer b can be connected to another power source. .

Claims (1)

PATENT CLAIMS: i. Device for generating a permanent pendulum movement the drop handle or similar organs to write or to control processes Measuring devices serving by means of electrical contacts, characterized in that Bimetal strips are provided by their alternating heating and cooling the movement of the drop bar is controlled and at the same time the own electric heating is automatically switched on and off alternately. a. Device according to Claim i, characterized in that for switching on and off the heating of the bimetallic strip is provided with a toggle switch. 3. Establishment according to claim z for alternating current supply via a transformer, characterized in that that the primary current of the supply transformer is switched on and off by the toggle switch will. q .. Device according to claim i, characterized in that the drop bracket attached to bimetallic strips in series with the controlling bimetallic strip are switched. 5. Device according to claim q., Characterized in that several Drop stirrups are connected in series with the controlling bimetal strip. , 6th establishment according to claim i, characterized in that the drop bracket consists of a bimetallic strip is controlled mechanically. 7. Establishment. according to claim r, characterized in that that the drop bracket is controlled indirectly by the bimetal strip, 8th device according to claim 7, characterized in that the bimetal strip has a contact device which is the circuit of an electromagnet driving the drop bracket alternately opens and closes.